Targeted degradation of pathogenic TDP-43 proteins in amyotrophic lateral sclerosis using the AUTOTAC platform
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons and the cytoplasmic aggregation of misfolded proteins in the spinal cord, including TAR DNA-binding protein-43 (TDP-43). More than 97% of ALS cases exhibit pathological TDP-43 inclusions, yet therapeutic strategies that can selectively eliminate these aggregates remain yet to be developed. Here, we employed the AUTOTAC (Autophagy-Targeting Chimera) to degrade TDP-43 aggregates via macroautophagy mediated by the N-recognin p62/SQSTM1 of the N-degron pathway. The AUTOTAC degraders ATC141 and ATC142 were designed to bind and link the oligomeric species of misfolded TDP-43 to p62, which induces the targeting of TDP-43 cargoes to phagophores for lysosomal co-degradation, while sparing monomeric TDP-43. ATC142 induced the degradation of pathological TDP-43 A315T species and its cleaved variant, TDP-25, with DC50 values of 1.25-9.6 nM. In ALS model mice expressing TDP-43 A315T in the spinal cord, oral administration of 10 mg/kg ATC141 with 24 doses reduced TDP-43 aggregates as well as GFAP+ astrocytes and Iba1+ microglia. ATC141 also exerted disease-modifying efficacy to reverse the disease progression in neuromuscular coordination and cognitive function. This oral drug is under Phase 1 clinical trials in South Korea with 76 healthy volunteers aiming to treat ALS, Alzheimer's diseases (AD), and progressive supranuclear palsy (PSP). We suggest that AUTOTAC provides a novel strategy to treat a broad range of neurodegenerative diseases.